<script>
    function fileSizeToString(size) {
        var data = "";
        if (size < 0.1 * 1024) { //如果小于0.1KB转化成B
            data = size.toFixed(2) + "B";
        } else if (size < 0.1 * 1024 * 1024) {//如果小于0.1MB转化成KB
            data = (size / 1024).toFixed(2) + "KB";
        } else if (size < 0.1 * 1024 * 1024 * 1024) { //如果小于0.1GB转化成MB
            data = (size / (1024 * 1024)).toFixed(2) + "MB";
        } else { //其他转化成GB
            data = (size / (1024 * 1024 * 1024)).toFixed(2) + "GB";
        }
        var sizestr = data + "";
        var len = sizestr.indexOf("\.");
        var dec = sizestr.substr(len + 1, 2);
        if (dec === "00") {//当小数点后为00时 去掉小数部分
            return sizestr.substring(0, len) + sizestr.substr(len + 3, 2);
        }
        return sizestr;
    }
</script>